lumo-mcp-app

Build MCP App servers that deliver interactive HTML user interfaces to hosts like Claude.ai and ChatGPT. Use when creating MCP servers with UI resources, building interactive tools with visual output, or implementing bidirectional communication between iframe UIs and MCP hosts. Covers the ui:// resource scheme, tool-UI linkage, postMessage JSON-RPC transport, CSP security, and sandbox architecture. Triggers on: "MCP app", "MCP UI", "ui:// resource", "interactive MCP tool", "MCP server with interface", "MCP iframe".